1. Field of the Invention
The present invention relates to a small-animal imaging system, and more particularly to a multi-rail imaging system for maintaining a desired image plane during an imaging session.
2. Description of the Prior Art
Over the past few years researchers in disciplines as diverse as neuroscience, developmental biology, genetics, and oncology have struggled with the challenge of injecting microliter and nanoliter quantities of fluid into discrete regions of organ systems. With the development and launch of ultrasound biomicroscopy (UBM) technology in the small animal imaging marketplace, the capacity to non-invasively observe, in real-time, the position of a needle or probe relative to an organ became a reality. One disadvantage with present positioning systems for animals is that straightforward repeatability of position with different animals is not possible.
For example, during injections procedures, a common problem has been the challenge of aligning a needle guidance device, which injects very small quantities of fluid, with a UBM scanhead device. Micromanipulation of both devices is necessary to help ensure that the injector needle of the needle guidance device lies within the same plane as the ultrasound scanhead so that the operator can guide the needle to the organ of interest. Consequently, this is a laborious and time-consuming process, which is aggravated by the need to move both devices away from an animal handling device, upon which a small animal is mounted, when a different animal is to be scanned. Current systems use independent, non-integrated, positioning methods for the various devices used in the imaging session.
Much information and expertise is available on the sequence and the manipulation of the mouse genome. Because of the similarity between the mouse and human genomes, the mouse is used as a model for understanding human gene function, and a model for many human disease processes. Manipulations permitted by guided injection technique facilitate experiments to further the understanding of genome function, the functional stages of organ development, the differentiation of stem cells, and facilitate testing of new interventions for models of human disease. Ultrasound imaging can be used to generate a high resolution, cross sectional image in real-time so the imaging system can be operated while a needle is introduced into the small animal that gives the operator immediate accurate feedback for positioning of the needle tip in the target space. However, there is a need for providing a system to provide for quick manipulation of imaging apparatus and, if used, injection apparatus, around a sequence of different animals in a time efficient manner.
There is a further need for a mounting table for handling of small animals, such as mice, rats, rabbits, and the like, in both a minimally stressful and time efficient manner during the course of an imaging session. Control of the animal's physiological condition is of paramount concern, but doing so in an environment that permits the movement of the immobilized subject in a variety of positions to maximize the success of placing the animal within the imaging plane of the imaging apparatus. Further complicating these procedures is the fact that some protocols necessitate that the embryos of pregnant animals be externalized from the abdomen to provide for improved imaging resolution.
To date, no device serves each of the needs outlined to enable the safe and effective delivery of anaesthesia to small animals, the physiological monitoring of the immobilized subject, the capacity for a range of motion, and the ability to successfully externalize embryos on a specialized table.